Can't Stomach Raw Tomatoes? Here's The Science Behind Why

A sweet, plump cherry tomato or a glistening, ripe heirloom tomato are both a far cry from some of the sad, pale tomatoes that tend to be found in the grocery store, especially outside of the summer months in which they thrive. An out of season, factory farmed tomato is bound to ruin a sandwich with it's soggy texture and lack of flavor. But there are some people who, no matter the perfection or quality of a tomato, just cannot bring themselves to consume the raw fruit (yes, tomatoes are a fruit!). While it's easy to assume they are simply picky eaters, there may be more at play, such as a nightshade allergy or susceptibility to heartburn.

Tomatoes were once thought of as poisonous due to their association with nightshades, one of which is the toxic and deadly belladonna. While tomatoes are thankfully not poisonous nor deadly, they are a part of the nightshade family, which includes eggplants, chilis, bell peppers, and white potatoes. Some people are allergic to the these flowering plants due to chemicals known as alkaloids. While a true allergy is somewhat rare, nightshade intolerance can still cause some troublesome gastrointestinal symptoms after consuming them. Tomatoes are also highly acidic, which can contribute to heartburn, a distinctly unpleasant experience, and therefore lead some people to avoiding the raw fruit.

For some raw tomato haters, it's the texture that can be off-putting, as the fruits can be slimy or mealy if they aren't perfectly firm and ripe. And the seeds are coated in a gelatinous membrane, which can also drive eaters away. In terms of flavor, though they can vary greatly, some people may just flat out not enjoy the combinations of flavor compounds in a tomato, which are a mix of acids, sugar, and what scientists refer to as volatile organic compounds (or VOCs). There are more than 400 VOCs found in tomatoes, and these variations can dramatically affect both their flavor and how we perceive their taste.

Personally, as a chef and general produce enthusiast, my inability to consume raw tomatoes is one of my worst qualities, and it continues to be the bane of my culinary existence. I stare longingly at multicolor heirloom tomatoes shimmering in the Los Angeles sun at farmers markets and am always embarrassed when I'm forced to discard the tomato slices of a perfectly composed caprese salad. I have tried time and time again to eat them, but there's something about the acidic-yet-watery, vegetal flavor that I absolutely cannot stomach. Cutting large amounts of raw tomatoes irritates my skin, and even the smell of a tomato plant elicits a nauseous feeling. While there are some scientific reasons behind why certain people are raw tomato adverse, like a nightshade allergy, it may also just boil down to personal preference and taste receptors.